The objective of this project is to analyze and characterize a collagenolytic enzyme from a variety of head and neck tumors and to determine the significance of collagenolysis in the invasiveness andclinical behavior of these malignancies in human and in an experimental epidermoid tumor in rats. The current research was to compare the levels of collagenase and protease activities according to the anatomic site, histological pattern (i.e., squamous versus nonsquamous), tumor size and tumor differentiation. We have also studied the effect of prostaglandin (possibly a chemical mediator for tumor growth and spread) on the synthesis and the release of collagenase and protease. The animal model also will be used to study immunoinhibition of collagenase in vitro and in vivo to test whether immunoinhibition of collagenase will decrease tumor invasiveness and improve animal survival. We hope that from these studies, a treatment plan for head and neck tumors can be placed on a more rational basis.